Academic Integrity: tutoring, explanations, and feedback — we don’t complete graded work or submit on a student’s behalf.

Part A A 1.0-L buffer solution is 0.115 Min HNO2 and 0.185 Min NaNO2 Dotarmine t

ID: 1035825 • Letter: P

Question

Part A A 1.0-L buffer solution is 0.115 Min HNO2 and 0.185 Min NaNO2 Dotarmine the ooncentrations of HNO2 and NaNO, after addition of 1.4 g HCL Express your answers using three significant figures separated by a comma. ?? HNO2). NaNO ]173.,.116 Submit Previous Answers Request Answer Incorrect; Try Again; 4 attempts remaining Part B Determine the concentrations of HNO2 and NaNO; ater addition of 1.4 g NaOH Express your answers using three significant figures separated by a comma. Submit Request Answer

Explanation / Answer

1 L buffer solution is 0.115 M in HNO2 (0.115 moles of HNO2) and 0.185 M in NaNO2 (0.185 moles of NaNO2)

Part A :- Determination of the concentrations of HNO2 and NaNO2 after addition of 1.4 g HCl

no. of moles of added HCl = given mass of HCl / molar mass of HCl

           molar mass of HCl = 1.01 + 35.45 = 36.46 g/mol
                                      = 1.4 g / 36.46 grams

                                      = 0.0384 moles


At equilibrium:- HNO2 <-------->    H+ + NO2-
                    0.115 mol        0.185 mol

On addition of HCl , H+ ions shifts equilibrium to the left.

HNO2            <-------->    H+ + NO2-

0.115 + 0.0384               0.185 - 0.0384
0.1534 mol                             0.1466 mol

Concentrations after addition of HCl concentration is 0.153 M HNO2 and 0.146 M NaNO2

Part B :-Determination of the concentrations of HNO2 and NaNO2 after addition of 1.4 g NaOH

no. of moles of added NaOH = given mass of NaOH / molar mass of NaOH

           molar mass of NaOH = 23 + 16 + 1 = 40 g/mol
                                      = 1.4 g / 40 grams

                                      = 0.035 moles

At equilibrium:- HNO2 <-------->    H+ + NO2-
                    0.115 mol        0.185 mol

On addition of NaOH ,OH- ions removes H+ ions and shift of the equilibrium to the right.

HNO2            <-------->    H+ + NO2-

0.115 - 0.0384               0.185 + 0.0384
0.0766 mol                          0.2234 mol

Concentrations after addition of 1.4g of NaOH concentration is 0.0766 M HNO2 and 0.2234 M NaNO2

Hire Me For All Your Tutoring Needs
Integrity-first tutoring: clear explanations, guidance, and feedback.
Drop an Email at
drjack9650@gmail.com
Chat Now And Get Quote